The invention relates to an apparatus for the testing of a brake system which includes a brake pressure source, a brake line, and at least one brake cylinder and further contains at least one brake pressure control valve mechanism which is arranged to release, in one of its attitudes, a pressure into a pressureless outlet line. This testing apparatus further includes a pressure sensor, a controller serving to effect differing pressure conditions and pressure courses by the actuation of valves and a discriminator which compares the actual pressures gauged by means of the pressure sensor with the optimal pressures programmed for specific time points on the basis of the given valve actuation by the controller. The discriminator reveals the condition of the brake system based upon the comparison made by the apparatus.
A generally similar testing apparatus is disclosed in the German laid-open application 2,342,307, especially in FIG. 4 thereof. In that apparatus, the pressure sensor is connected ahead of the valve controlling the brake pressure in the system.